Looks like you sent the right accommodation evidence (though you didn't need the council bill).
May have been overkill on the relationship stuff. Shouldn't have been more than 2 photos and a few pages of communication (say 10 at a stretch). It may be they are wading through that looking for the required documents.
What did you send for financials?
Did you send 6 FULL months of payslips that clearly stated from the 1st of the month to the 31st of the month? If the payslips don't list the start date, we suggest 7.
Did you send 6 FULL months of bank statements that cover the same date range of the payslips at a minimum? Usually these need to be a bit longer on than just exactly six months to ensure you show all 6 or 7 deposits.
Did you send the letter from the employer stating the start date, salary, any increases in salary, and the type of position?
Did you send a signed letter from your sponsor?
Did you send appendix 2?
If all of those are yes, then it's likely the email that triggered the not straight forward response.
